More on environment

WASHINGTON — Nearly one in three of the nation's nuclear plant operators is failing to report potentially risky equipment defects because of contradictory and unclear regulations, according to an audit released Thursday.

Unless the Nuclear Regulatory Commission takes steps to improve its reporting guidelines, the "margin of safety for operating reactors could be reduced," the agency's Office of Inspector General's report said.

The study comes as questions are raised about the safety of U.S. nuclear facilities in the wake of the nuclear crisis in Japan. No specific nuclear plants are mentioned in the 16-page audit.

Reflecting that confusion, the report said the NRC has not levied any civil penalties or significant enforcement actions against nuclear plant operators for lapses in reporting equipment defects in at least eight years.

The auditors found at least 24 instances where possible equipment defects were identified but not reported to the agency from December 2009 through September of last year, according to the study.

NRC officials said the audit focused on administration.

"The report from the NRC's Office of Inspector General is focused on a subset of defects, specifically manufacturing defects," said NRC spokesman Neil Sheehan. "Both utilities and NRC inspectors have processes for identifying and reporting manufacturing defects. The fundamental issue identified by the report is administrative and pertains to how these defects are reported."

Sheehan said the agency has a "variety of other regulations that effectively encompass reporting all defects."

The NRC continues to conclude plants are operating safely, but the agency will look at the report to see if its reporting systems can be improved, Sheehan said.

The agency, after the Japan earthquake and tsunami, has said the 104 commercial reactors it oversees can withstand such a natural disaster, but is conducting a 90-day review to see if regulations need to be tightened.

One area of discrepancy was whether a defect actually caused a problem at a nuclear plant or merely could have caused one.

"Typically, safety functions are supported by multiple redundant components — such as multiple service water pumps — so that loss of a single component does not cause a loss of safety function," the report states. Later the report notes that current regulations "may result in the under-reporting of defects."

At least 28 percent of the operating reactor fleet does not, as standard practice, notify NRC of defects under one set of regulations unless the defects are reportable under tighter event-reporting regulations, auditor said.

The IG said the NRC's baseline inspection program does not require inspectors to review an operator's reporting on equipment defects.

"(NRC) has not yet established a position that would result in consistent interpretation and application of ... guidance and regulations on the part of NRC staff and resident inspectors, as well as licensees," the report said.

An attempt to reach Indian Point officials late Thursday was unsuccessful.